Solenoids with a tube pipe and a magnet body arranged on it are known. For connecting magnet body and tube pipe the magnet body is slipped on, slid on or pressed on the tube pipe, and thus more or less permanently connected with the tube pipe. The tube pipe serves here as guide of a magnet armature which can be moved by loading with current.
As a rule solenoids have a protective conductor which is arranged in such a way that an electric connection is produced between the metal parts of the solenoid and the ground. It is, in particular, important here that the protective conductor contacts all metallic parts of the solenoid. In conventional solenoids having a magnet body slid or pressed on the tube pipe after a long use which not seldom is accompanied by vibrations, a separation of the connection between the tube pipe and the magnet body occurs. With this separation often also the protective conduction is interrupted so that the grounding of the solenoid is no more sufficient. In addition to that, caused by the fact that the magnet body is separated from the tube pipe, also function error of the solenoid may occur which is not desired in permanent operation, and leads to standstill times as well as expenses for repair and thus costs.